What do brain oscillations tell about the human sense of smell?

Brain activity may manifest itself as oscillations which are repetitive rhythms of neuronal firing. These local field potentials can be measured via intracranial electroencephalography (iEEG). This review focuses on iEEG used to map human brain structures involved in olfaction. After presenting the methodology of the review, a summary of the brain structures involved in olfaction is given, followed by a review of the literature on human olfactory oscillations in different contexts. A single case is provided as an illustration of the olfactory oscillations. Overall, the timing and sequence of oscillations found in the different structures of the olfactory system seem to play an important role for olfactory perception.

The importance of the bacterial spectrum in the clinical diagnostics and management of patients with spontaneous pyogenic spondylodiscitis and isolated spinal epidural empyema: a 20-year cohort study at a single spine center.

BACKGROUND: Personalized clinical management of spondylodiscitis (SD) and isolated spinal epidural empyema (ISEE) is challenging due to limited evidence of microbiologic findings and their clinical impact during the clinical course of the disease. We aimed to characterize clinico-microbiological and imaging phenotypes of SD and ISEE to provide useful insights that could improve outcomes and potentially modify guidelines. METHODS: We performed chart review and collected data on the following parameters: bacterial antibiogram-resistogram, type of primary spinal infection, location of spinal infection, source of infection, method of detection, clinical complications (sepsis, septic embolism, and endocarditis), length of hospital and intensive care unit (ICU) stay, relapse rate, and disease-related mortality in patients with proven pyogenic SD and ISEE treated surgically in a university hospital in Germany between 2002 and 2022. RESULTS: We included data from 187 patients (125 SD, 66.8% and 62 ISEE, 33.2%). Gram-positive bacteria (GPB) were overall more frequently detected than gram-negative bacteria (GNB) (GPB: 162, 86.6% vs. GNB: 25, 13.4%, p < 0.001). Infective endocarditis was caused only by GPB (GPB: 23, 16.5% vs. GNB: 0, 0.0%, p = 0.046). Methicillin-susceptible Staphylococcus aureus was the most frequently isolated strain (MSSA: n = 100, 53.5%), occurred more frequently in the cervical spine compared to other bacteria (OB) (MSSA: 41, 41.0% vs. OB: 18, 20.7%, p = 0.004) and was most frequently detected in patients with skin infection as the primary source of infection (MSSA: 26, 40.6% vs. OB: 11, 16.7%, p = 0.002). Streptococcus spp. and Enterococcus spp. (SE: n = 31, 16.6%) were more often regarded as the cause of endocarditis (SE: 8, 27.6% vs. OB: 15, 11.4%, p = 0.037) and were less frequently detected in intraoperative specimens (SE: 19, 61.3% vs. OB: 138, 88.5%, p < 0.001). Enterobacterales (E: n = 20, 10.7%) were identified more frequently in urinary tract infections (E: 9, 50.0% vs. OB: 4, 3.6%, p < 0.001). Coagulase-negative Staphylococci (CoNS: n = 20, 10.7%) were characterized by a lower prevalence of sepsis (CoNS: 4, 20.0% vs. OB: 90, 53.9%, p = 0.004) and were more frequently detected in intraoperative specimens (CoNS: 20, 100. 0% vs. OB: 137, 82.0%, p = 0.048). Moreover, CoNS-associated cases showed a shorter length of ICU stay (CoNS: 2 [1-18] days vs. OB: 6 [1-53] days, median [interquartile range], p = 0.037), and occurred more frequently due to foreign body-associated infections (CoNS: 8, 61.5% vs. OB: 15, 12.8%, p = 0.008). The presence of methicillin-resistant Staphylococcus aureus (MRSA) prolonged hospital stay by 56 [24-58] days and ICU stay by 16 [1-44] days, whereas patients with Pseudomonas aeruginosa spent only 20 [18-29] days in the hospital and no day in the ICU 0 [0-5] days. CONCLUSIONS: Our retrospective cohort study identified distinct bacterial-specific manifestations in pyogenic SD and ISEE regarding clinical course, neuroanatomic targets, method of pathogen detection, and sources of infection. The clinico-microbiological patterns varied depending on the specific pathogens.

Surgical results of 158 petroclival meningiomas with special focus on standard craniotomies.

OBJECTIVE: The goal of this retrospective study is the evaluation of risk factors for postoperative neurological deficits after petroclival meningioma (PCM) surgery with special focus on standard craniotomies. MATERIALS AND METHODS: One-hundred-fifty-eight patients were included in the study, of which 133 patients suffered from primary and 25 from recurrent PCM. All patients were operated on and evaluated concerning age, tumor size, histology, pre- and postoperative cranial nerve (CN) deficits, morbidity, mortality, and surgical complications. Tumor-specific features-e.g., consistency, surface, arachnoid cleavage, and location-were set in a four-grade classification system that was used to evaluate the risk of CN deficits and tumor resectability. RESULTS: After primary tumor resection, new CN deficits occurred in 27.3% of patients. Preoperative ataxia improved in 25%, whereas 10% developed new ataxia. Gross total resection (GTR) was achieved in 59.4%. The morbidity rate, including hemiparesis, shunt-dependence, postop-hemorrhage, and tracheostomy was 22.6% and the mortality rate was 2.3%. In recurrent PCM surgery, CN deficits occurred in 16%. GTR could be achieved in three cases. Minor complications occurred in 20%. By applying the proposed new classification system to patients operated via standard craniotomies, the best outcome was observed in type I tumor patients (soft tumor consistency, smooth surface, plane arachnoid cleavage, and unilateral localization) with GTR in 78.7% (p < 0.001) and 11.9% new CN deficits (p = 0.006). CONCLUSION: Standard craniotomies as the retrosigmoid or subtemporal/pterional approaches are often used for the resection of PCMs. Whether these approaches are sufficient for GTR-and avoidance of new neurological deficits-depends mainly on the localization and intrinsic tumor-specific features.

Clinical assessment of olfactory function.

Approximately 5% of the general population is affected by functional anosmia with approximately additional 15% exhibiting decreased olfactory function. Many of these individuals ask for help. Because the subjective rating of olfactory function is biased, assessment of olfactory function is important. Olfactory measurements are needed for patient counseling and the tracking of changes in the sense of smell over time. The present review provides an overview of frequently used psychophysical tests for olfactory function, discusses differences between threshold and suprathreshold aspects of olfactory function, and gives examples on how to apply psychophysical tests.

Parcellation of the Subthalamic Nucleus in Parkinson's Disease: A Retrospective Analysis of Atlas- and Diffusion-Based Methods.

BACKGROUND: Deep brain stimulation (DBS) is an established method of treatment for Parkinson's disease (PD). A stimulation sweet spot at the interface between the motor and associative clusters of the subthalamic nucleus (STN) has recently been postulated. The aim of this study was to analyze the available clustering methods for the STN and their correlation to outcome. METHODS: This is a retrospective analysis of a group of 20 patients implanted with a DBS device for PD. Atlas-based and diffusion tractography-based parcellation of the STN was performed. The distances of the electrode to the obtained clusters were compared to each other and to outcome parameters, which included levodopa equivalent dose (LED) reduction, Unified Parkinson's Disease Rating Scale (UPDRS)-III scores, and reduction in scores for items 32 and 36 of the UPDRS-IV. RESULTS: The implanted electrodes were located nearest to the motor clusters of the STN. The following significant associations with postoperative LED reduction were found: (1) distance of the electrode to the motor cluster in the Accolla and DISTAL atlases (p < 0.01) and (2) distance of the electrode to the supplementary motor area cluster (p = 0.02). There was no association with either the UPDRS-III or the UPDRS-IV score. CONCLUSIONS: The results of this study suggest the possibility that atlas-based clustering, as well as diffusion tractography-based parcellation, can be useful in estimating the stimulation target ("sweet spot") for STN-DBS in PD patients. Atlas-based as well as diffusion-based clustering might become a useful tool in DBS trajectory planning.

International multicentre validation of the arteriovenous malformation-related intracerebral haemorrhage (AVICH) score.

OBJECTIVE: The recently published arteriovenous malformation-related intracerebral haemorrhage (AVICH) score showed better outcome prediction for patients with arteriovenous malformation (AVM)-related intracerebral haemorrhage (ICH) than other AVM or ICH scores. Here we present the results of a multicentre, external validation of the AVICH score. METHODS: All participating centres (n=11) provided anonymous data on 325 patients to form the Spetzler-Martin (SM) grade, the supplemented SM (sSM) grade, the ICH score and the AVICH score. Modified Rankin score (mRS) at last follow-up (mean 25.6 months) was dichotomized into favourable (mRS 0-2, n=210) and unfavourable (mRS 3-6;n=115). Univariate and AUROC analyses were performed to validate the AVICH score. RESULTS: Except nidus structure and AVM size, all single parameters forming the SM, sSM, ICH and AVICH score and the scores itself were significantly different between both outcome groups in the univariate analysis. The AVICH score was confirmed to be the highest predictive outcome score with an AUROC of 0.765 compared with 0.705 for the ICH score and 0.682 for the sSM grade. CONCLUSION: The multicentre-validated AVICH score predicts clinical outcome superior to pre-existing scores. We suggest the routine use of this score for future clinical outcome prediction and in clinical research. TRIAL REGISTRATION NUMBER: NCT02920645.

Enhancing tumor apparent diffusion coefficient histogram skewness stratifies the postoperative survival in recurrent glioblastoma multiforme patients undergoing salvage surgery.

Objective To determine the value of apparent diffusion coefficient (ADC) histogram parameters for the prediction of individual survival in patients undergoing surgery for recurrent glioblastoma (GBM) in a retrospective cohort study. Methods Thirty-one patients who underwent surgery for first recurrence of a known GBM between 2008 and 2012 were included. The following parameters were collected: age, sex, enhancing tumor size, mean ADC, median ADC, ADC skewness, ADC kurtosis and fifth percentile of the ADC histogram, initial progression free survival (PFS), extent of second resection and further adjuvant treatment. The association of these parameters with survival and PFS after second surgery was analyzed using log-rank test and Cox regression. Results Using log-rank test, ADC histogram skewness of the enhancing tumor was significantly associated with both survival (p = 0.001) and PFS after second surgery (p = 0.005). Further parameters associated with prolonged survival after second surgery were: gross total resection at second surgery (p = 0.026), tumor size (0.040) and third surgery (p = 0.003). In the multivariate Cox analysis, ADC histogram skewness was shown to be an independent prognostic factor for survival after second surgery. Conclusion ADC histogram skewness of the enhancing lesion, enhancing lesion size, third surgery, as well as gross total resection have been shown to be associated with survival following the second surgery. ADC histogram skewness was an independent prognostic factor for survival in the multivariate analysis.

The impact and prospect of traumatic brain injury on olfactory function: a cross-sectional and prospective study.

Traumatic brain injury (TBI) can cause olfactory loss. The aim of this cross-sectional and prospective study was to determine the prevalence of olfactory loss among 110 patients with TBI within 3 months after the trauma. In 81 patients ("cross-sectional"-group), olfactory function could be measured using the validated "Sniffin' Sticks" test for odor threshold and odor identification. In addition, the prospective change of olfactory function was studied in 36 patients ("follow-up"-group) by means of a validated odor threshold, discrimination and identification test. Olfactory function was significantly better in patients with TBI I° compared to individuals with TBI II° and III°. Clinically significant improvement of olfactory function was found in 36% of the patients, most frequently during the first 6 months after the injury, in a median follow-up interval of 21 months. TBI I° has in general no major effect on olfaction. In contrast, patients with TBI II° and III° exhibit smell loss in 57%. Chances for olfactory recovery were highest within the first 6 months after the trauma.

Diagnostic, clinical management, and outcomes in patients with spinal dural arteriovenous fistula.

Background: Spinal dural arteriovenous fistulas (SDAVFs) are rare spinal vascular malformations, but account for 70 to 80% of all spinal arteriovenous malformations. SDAVFs can be treated either surgically or endovascularly, with surgical treatment appearing to lead to higher closure rates. Our aim was to analyze the demographic data, diagnostic history, treatment characteristics and clinical short- and long-term outcomes. Methods: The medical records of 81 patients who underwent surgical (n = 70, 86.4%) and endovascular (n = 11, 13.6%) treatment for SDAVF at a university hospital between 2002 and 2023 were retrospectively analyzed. Results: SDAVF was observed more frequently in men than women (61, 75.3% vs. 20, 24.7%) with a mean age of 63.5 ± 12.7 years and a mean duration of symptoms to diagnosis of 12.0 ± 12.8 months. The most common first symptom was gait disturbance (36, 44.4%), followed by sensory disturbance (24, 29.6%). The location of the fistula point was most common in the lower thoracic region (36, 44.5%), followed by the lumbar region (23, 28.4%). Incomplete or failed occlusion of the fistula occurred in 8 patients (9.9%), with 6 patients (7.4%) undergoing further treatment either surgically or endovascularly. Treatment- or hospital-related complications were observed in 16 patients (19.8%). A single-level laminectomy was the most common approach (31, 44.3%), followed by single-level hemilaminectomy (28, 40.0%), and unilateral interlaminar fenestration (11, 15.7%). Back pain or radiculopathy was observed in 58% of patients (47/81) pre-treatment and had already decreased to 24.7% at hospital discharge (p < 0.001). No significant differences were observed in sensory disturbances (p = 0.681). The median of American Spinal Injury Association motor score (ASIA-MS) was 94 [82.5-100] at admission, 98 [86.5-100] at hospital discharge, 100 [90-100] at the first, second, and third follow-up (p = 0.019). The median modified Aminoff-Logue scale (mALS) was 5 [2-7] at admission, 3 [1-6] at hospital discharge, 2 [1-5] at the first follow-up, 2 [0.5-5] at the second follow-up and 2 [1-7] at the third follow-up (p = 0.006). Conclusions: SDAVF occurs predominantly in men in the 6th decade of life and can be safely and effectively treated surgically and endovascularly, improving symptoms such as pain and motor deficits, gait disturbances as well as bowel and bladder dysfunction, but not sensory disturbances.

The Impact of Magnetic Resonance Imaging Findings in Predicting Neurological Status Pre- and Post-Treatment of Spinal Dural Arteriovenous Fistulas: A 22-Year Experience in a Neurovascular and Spine Center.

BACKGROUND: Successful treatment of spinal dural arteriovenous fistulas (SDAVF) requires prompt diagnosis with definitive fistula localization and non-delayed treatment. Magnetic resonance imaging (MRI) is used for the screening and follow-up of SDAVF, although the value of MRI signs such as myelopathy and flow voids is controversial. Therefore, we investigated the predictive value of MRI signs pre- and post-treatment and their correlation with the neurological status of SDAVF patients. METHODS: We retrospectively analyzed the clinical records of 81 patients who underwent surgical or endovascular treatment for SDAVF at our hospital between 2002 and 2023. A total of 41 SDAVF patients with follow-up MRI of 4.6 [2.9-6.5] months (median [interquartile range]) post-treatment and clinical follow-up of 3, 6, and 12 months were included. RESULTS: The extent of pretreatment myelopathy was seven [6-8] vertebral levels, with follow-up MRI showing no myelopathy in 70.7% of cases. The pretreatment flow voids extended over seven [4.5-10] vertebral levels and completely disappeared on follow-up MRI in 100% of cases. The modified Aminoff-Logue scale of disability (mALS) was four [2-7] pretreatment and two [0-4.5] at the third follow-up, with improvement in 65.9% of patients. The American Spinal Injury Association motor score (ASIA-MS) was 97 [88-100] pretreatment and 100 [95-100] at the third follow-up assessment, with 78% of patients improving. Pretreatment ASIA-MS correlated with the extent of myelopathy at admission (R2: 0.179; 95% CI: -0.185, -0.033; p = 0.006) but not with flow voids at admission, while pretreatment mALS showed no correlation with either MRI signs. The improvement in ASIA-MS and mALS between admission and the last follow-up showed no correlation with the extent of pretreatment myelopathy and flow voids or with pos-treatment MRI changes. The diagnostic sensitivity of magnetic resonance angiography (MRA) for localization of the fistula was 68.3% (28/41). CONCLUSIONS: The severity of the clinical condition in SDAVF patients has a multifactorial cause, whereby the ASIA-MS correlates with the extent of myelopathy pretreatment. MRI changes after treatment showed no correlation with the clinical outcome and cannot be used as a prognostic factor.

Correlation of Molecular Status with Preoperative Olfactory Function in Olfactory Groove Meningioma.

PURPOSE: The study aims to examine the possible correlation between genomic alterations and preoperative olfactory function in patients with olfactory groove meningioma (OGM), due to the frequent presence of olfactory impairment. METHODS: We utilised next-generation sequencing to analyse samples from 22 individuals with OGM in order to detect driver mutations. Tumour morphology was assessed using preoperative imaging, whereas olfactory function was examined using Sniffin' Sticks. RESULTS: In a study of 22 OGM patients, mutations were as follows: 10 with SMO/SUFU, 7 with AKT1, and 5 as wild type. Planum sphenoidale hyperostosis (PSH) was present in 75% of patients, showing significant variation by mutation (p = 0.048). Tumour volumes, averaging 25 cm3, significantly differed among groups. PSH negatively impacted olfaction, notably affecting odour threshold, discrimination, identification, and global olfactory performance score (TDI) (p values ranging from <0.001 to 0.003). Perifocal oedema was associated with lower TDI (p = 0.009) and altered threshold scores (p = 0.038). Age over 65 and female gender were linked to lower thresholds and discrimination scores (p = 0.037 and p = 0.019). CONCLUSION: The study highlights PSH and perifocal oedema's significant effect on olfactory function in OGM patients but finds no link between olfactory impairment and tumour mutations, possibly due to the small sample size. This suggests that age and gender affect olfactory impairment. Additional research with a larger group of participants is needed to explore the impact of OGM driver mutations on olfactory performance.

Trigeminal Sensory Neuropathy Predicts Chemosensory Dysfunction After Skull Base Surgery.

BACKGROUND: Trigeminal sensory neuropathy, characterized by diminished or exaggerated/painful sensation along the distribution of trigeminal branches, is one of the complications after skull base surgery. These procedures can also affect chemosensory functions and compromise the patients' quality of life. OBJECTIVE: To examine those postoperative complications in chemosensory and facial cutaneous sensory functions as well as their interaction. METHODS: A total of 61 patients being operated for various pathologies in the vicinity of trigeminal pathway (17 with trigeminal neuralgia, 20 with meningiomas, and 24 with vestibular schwannomas) and 50 healthy controls were enrolled in this case-control study. Postoperative trigeminal neuropathic symptoms were evaluated. The olfactory, gustatory, and intranasal trigeminal functions were assessed using the Sniffin' Stick olfactory test, lateralized taste strip test, and the lateralized intranasal trigeminal CO 2 detection thresholds, respectively. RESULTS: Patients with trigeminal neuralgia and meningioma had relatively decreased olfactory function, whereas those with vestibular schwannoma had a relative decrease in taste function. As for the relationship between the distribution of trigeminal neuropathy and chemosensory dysfunction, we found that V3 involvement predicted lower side-specific taste function. In addition, V2/V3 involvement predicted relatively lower side-specific intranasal trigeminal function. CONCLUSION: The present results suggest a differential involvement of the chemical senses in relation to the site and pathology of the lesions after surgery. The presence of trigeminal neuropathy is associated with taste and intranasal trigeminal dysfunction. The results serve as a basis for consultation regarding outcome prediction and patient education.

The Efficacy of Daily Local Antibiotic Lavage via an Epidural Suction-Irrigation Drainage Technique in Spondylodiscitis and Isolated Spinal Epidural Empyema: A 20-Year Experience of a Single Spine Center.

BACKGROUND: Various treatment modalities are available for local antibiotic therapy in spondylodiscitis (SD) and isolated spinal epidural empyema (ISEE), but there is no evidence-based recommendation. Postoperative epidural suction-irrigation drainage (ESID) is thought to reduce bacterial load, which may prevent the development of relapse, wound healing, hematogenous spread, and systemic complications. We evaluated the efficacy of postoperative ESID over 20 years on disease progression and outcome in SD and ISEE. METHODS: Detailed demographic, clinical, imaging, laboratory, and microbiological characteristics were examined in our cohorts of 208 SD and ISEE patients treated with and without ESID at a university spine center in Germany between 2002 and 2022. Between-group comparisons were performed to identify meaningful differences for the procedure. RESULTS: We included data from 208 patients (142 SD, 68.3% vs. 66 ISEE, 31.7%) of whom 146 were ESID patients (87 SD, 59.6% vs. 59 ISEE, 40.4%) and 62 were NON-ESID patients (55 SD, 88.7% vs. 7 ISEE, 11.3%). ESID patients with SD showed more frequent SSI (ESID: 22, 25.3% vs. NON-ESID: 3, 5.5%, p = 0.003), reoperations due to empyema persistence or instability (ESID: 37, 42.5% vs. NON-ESID: 12, 21.8%, p = 0.012), and a higher relapse rate (ESID: 21, 37.5% vs. NON-ESID: 6, 16.7%, p = 0.037) than NON-ESID patients with SD. The success rate in NON-ESID patients with SD was higher than in ESID patients with SD (ESID: 26, 29.9% vs. NON-ESID: 36, 65.6%, p < 0.001). Multivariate binary logistic regression analysis showed that ESID therapy (p < 0.001; OR: 0.201; 95% CI: 0.089-0.451) was a significant independent risk factor for treatment failure in patients with SD. CONCLUSIONS: Our retrospective cohort study with more than 20 years of experience in ESID technique shows a negative effect in patients with SD in terms of surgical site infections and relapse rate.

Diagnostic Sensitivity of Blood Culture, Intraoperative Specimen, and Computed Tomography-Guided Biopsy in Patients with Spondylodiscitis and Isolated Spinal Epidural Empyema Requiring Surgical Treatment.

BACKGROUND: the successful treatment of spondylodiscitis (SD) and isolated spinal epidural empyema (ISEE) depends on early detection of causative pathogens, which is commonly performed either via blood cultures, intraoperative specimens, and/or image-guided biopsies. We evaluated the diagnostic sensitivity of these three procedures and assessed how it is influenced by antibiotics. METHODS: we retrospectively analyzed data from patients with SD and ISEE treated surgically at a neurosurgery university center in Germany between 2002 and 2021. RESULTS: we included 208 patients (68 [23-90] years, 34.6% females, 68% SD). Pathogens were identified in 192 cases (92.3%), including 187 (97.4%) pyogenic and five (2.6%) non-pyogenic infections, with Gram-positive bacteria accounting for 86.6% (162 cases) and Gram-negative for 13.4% (25 cases) of the pyogenic infections. The diagnostic sensitivity was highest for intraoperative specimens at 77.9% (162/208, p = 0.012) and lowest for blood cultures at 57.2% (119/208) and computed tomography (CT)-guided biopsies at 55.7% (39/70). Blood cultures displayed the highest sensitivity in SD patients (SD: 91/142, 64.1% vs. ISEE: 28/66, 42.4%, p = 0.004), while intraoperative specimens were the most sensitive procedure in ISEE (SD: 102/142, 71.8% vs. ISEE: 59/66, 89.4%, p = 0.007). The diagnostic sensitivity was lower in SD patients with ongoing empiric antibiotic therapy (EAT) than in patients treated postoperatively with targeted antibiotic therapy (TAT) (EAT: 77/89, 86.5% vs. TAT: 53/53, 100%, p = 0.004), whereas no effect was observed in patients with ISEE (EAT: 47/51, 92.2% vs. TAT: 15/15, 100%, p = 0.567). CONCLUSIONS: in our cohort, intraoperative specimens displayed the highest diagnostic sensitivity especially for ISEE, whereas blood cultures appear to be the most sensitive for SD. The sensitivity of these tests seems modifiable by preoperative EAT in patients with SD, but not in those with ISEE, underscoring the distinct differences between both pathologies.

Clinical phenotyping of spondylodiscitis and isolated spinal epidural empyema: a 20-year experience and cohort study.

Background: The incidence of spondylodiscitis (SD) and isolated spinal epidural empyema (ISEE) has been increasing in the last decades, but the distinct differences between both entities are poorly understood. We aimed to evaluate the clinical phenotypes and long-term outcomes of SD and ISEE in depth. Methods: We performed a chart review and analyzed data from our cohorts of consecutive SD and ISEE patients who were treated and assessed in detail for demographic, clinical, imaging, laboratory, and microbiologic characteristics at a university neurosurgical center in Germany from 2002 to 2021. Between-group comparisons were performed to identify meaningful differences in both entities. Results: We included 208 patients (72 females: age 75 [75 32-90] y vs. 136 males: 65 [23-87] y, median [interquartile range], p < 0.001), of which 142 (68.3%) had SD and 66 (31.7%) had ISEE. Patients with SD were older than ISEE (ISEE: 62 y vs. SD: 70 y, p = 0.001). While SD was more common in males than females (males: n = 101, 71.1% vs. females: n = 41, 28.9%, p < 0.001), there was no sex-related difference in ISEE (males: n = 35, 53.0% vs. females: n = 31, 47.0%, p = 0.71). Obesity was more frequent in ISEE than in SD (ISEE: n = 29, 43.9% vs. SD: n = 37, 26.1%, p = 0.016). However, there were no between-group differences in rates of diabetes and immunodeficiency. In the entire study population, a causative pathogen was identified in 192 (92.3%) patients, with methicillin-susceptible staphylococcus aureus being most frequent (n = 100, 52.1%) and being more frequent in ISEE than SD (ISEE: n = 43, 65.2% vs. SD: n = 57, 40.1%, p = 0.003). SD and ISEE occurred most frequently in the lumbar spine, with no between-group differences (ISEE: n = 25, 37.9% vs. SD: n = 65, 45.8%, p = 0.297). Primary infectious sources were identified in 145 patients (69.7%) and among this skin infection was most common in both entities (ISEE: n = 14, 31.8% vs. SD: n = 25, 24.8%, p = 0.418). Furthermore, epidural administration was more frequent the primary cause of infection in ISEE than SD (ISEE: n = 12, 27.3% vs. SD: n = 5, 4.9%, p < 0.001). The most common surgical procedure in SD was instrumentation (n = 87, 61%) and in ISEE abscess evacuation (n = 63, 95%). Patients with ISEE displayed lower in-hospital complication rates compared to SD for sepsis (ISEE: n = 12, 18.2% vs. SD: n = 94, 66.2%, p < 0.001), septic embolism (ISEE: n = 4/48 cases, 8.3% vs. SD: n = 52/117 cases, 44.4%, p < 0.001), endocarditis (ISEE: n = 1/52 cases, 1.9% vs. SD: n = 23/125 cases, 18.4%, p = 0.003), relapse rate (ISEE: n = 4/46, 8.7% vs. SD: n = 27/92, 29.3%, p = 0.004), and disease-related mortality (ISEE: n = 1, 1.5% vs. SD: n = 11, 7.7%, p = 0.108). Patients with SD showed prolonged length of hospital stay (ISEE: 22 [15, 30] d vs. SD: 38 [29, 53] d, p < 0.001) and extended intensive care unit stay (ISEE: 0 [0, 4] d vs. SD: 3 [0, 12] d, p < 0.002). Conclusions: Our 20-year experience and cohort analysis on the clinical management of SD and ISEE unveiled distinct clinical phenotypes and outcomes in both entities, with ISEE displaying a more favorable disease course with respect to complications and relapse rates as well as disease-related mortality.

Diagnostics, Management, and Outcomes in Patients with Pyogenic Spinal Intra- or Epidural Abscess.

BACKGROUND: Owing to the lack of evidence on the diagnostics, clinical course, treatment, and outcomes of patients with extremely rare spinal intradural abscess (SIA) and spinal epidural abscess (SEA), we retrospectively analyzed and compared a cohort of patients to determine the phenotyping of both entities. METHODS: Over a period of 20 years, we retrospectively analyzed the electronic medical records of 78 patients with SIA and SEA. RESULTS: The patients with SIA showed worse motor scores (MS scores) on admission (SIA: 20 ± 26 vs. SEA: 75 ± 34, p < 0.001), more often with an ataxic gait (SIA: 100% vs. SEA: 31.8%, p < 0.001), and more frequent bladder or bowel dysfunction (SIA: 91.7% vs. SEA: 27.3%, p < 0.001) compared to the SEA patients. Intraoperative specimens showed a higher diagnostic sensitivity in the SEA patients than the SIA patients (SIA: 66.7% vs. SEA: 95.2%, p = 0.024), but various pathogens such as Staphylococcus aureus (SIA 33.3% vs. SEA: 69.4%) and Streptococci and Enterococci (SIA 33.3% vs. SEA: 8.1%, p = 0.038) were detected in both entities. The patients with SIA developed sepsis more often (SIA: 75.0% vs. SEA: 18.2%, p < 0.001), septic embolism (SIA: 33.3% vs. SEA: 8.3%, p = 0.043), signs of meningism (SIA: 100% vs. 18.5%, p < 0.001), ventriculitis or cerebral abscesses (SIA: 41.7% vs. SEA: 3.0%, p < 0.001), and pneumonia (SIA: 58.3% vs. SEA: 13.6%, p = 0.002). The mean MS score improved in both patient groups after surgery (SIA: 20 to 35 vs. SEA: 75 to 90); however, the SIA patients showed a poorer MS score at discharge (SIA: 35 ± 44 vs. SEA: 90 ± 20, p < 0.001). C-reactive protein (CrP) (SIA: 159 to 49 vs. SEA: 189 to 27) and leukocyte count (SIA: 15 to 9 vs. SEA: 14 to 7) were reduced at discharge. The SIA patients had higher rates of disease-related mortality (SIA: 33.3% vs. SEA: 1.5%, p = 0.002), had more pleural empyema (SIA: 58.3% vs. SEA: 13.6%, p = 0.002), required more than one surgery (SIA: 33.3% vs. SEA 13.6%, p = 0.009), were treated longer with intravenous antibiotics (7 ± 4 w vs. 3 ± 2 w, p < 0.001) and antibiotics overall (12 ± 10 w vs. 7 ± 3 w, p = 0.022), and spent more time in the hospital (SIA: 58 ± 36 vs. SEA: 26 ± 20, p < 0.001) and in the intensive care unit (SIA: 14 ± 18 vs. SEA: 4 ± 8, p = 0.002). CONCLUSIONS: Our study highlighted distinct clinical phenotypes and outcomes between both entities, with SIA patients displaying a markedly less favorable disease course in terms of complications and outcomes.

The impact of concomitant infective endocarditis in patients with spondylodiscitis and isolated spinal epidural empyema and the diagnostic accuracy of the modified duke criteria.

Background: The co-occurrence of infective endocarditis (IE) and primary spinal infections (PSI) like spondylodiscitis (SD) and isolated spinal epidural empyema (ISEE) has been reported in up to 30% of cases and represents a life-threatening infection that requires multidisciplinary management to be successful. Therefore, we aimed to characterize the clinical phenotypes of PSI patients with concomitant IE and furthermore to assess the accuracy of the modified Duke criteria in this specific population. Methods: We conducted a retrospective cohort study in consecutive SD and ISEE patients treated surgically at our University Spine Center between 2002 and 2022 who have undergone detailed phenotyping comprising demographic, clinical, imaging, laboratory, and microbiologic assessment. Comparisons were performed between PSI patients with IE (PSICIE) and without IE (PSIWIE) to identify essential differences. Results: Methicillin-susceptible Staphylococcus aureus (MSSA) was the most common causative pathogen in PSICIE group (13 patients, 54.2%) and aortic valve IE was the most common type of IE (12 patients, 50%), followed by mitral valve IE (5 patients, 20.8%). Hepatic cirrhosis (p < 0.011; OR: 4.383; 95% CI: 1.405-13.671), septic embolism (p < 0.005; OR: 4.387; 95% CI: 1.555-12.380), and infection with Streptococcus spp. and Enterococcus spp. (p < 0.003; OR: 13.830; 95% CI: 2.454-77.929) were identified as significant independent risk factors for the co-occurrence of IE and PSI in our cohort. The modified Duke criteria demonstrated a sensitivity of 100% and a specificity of 66.7% for the detection of IE in PSI patients. Pathogens were detected more frequently via blood cultures in the PSICIE group than in the PSIWIE group (PSICIE: 23, 95.8% vs. PSIWIE: 88, 62.4%, p < 0.001). Hepatic cirrhosis (PSICIE: 10, 41.7% vs. PSIWIE: 33, 21.6%, p = 0.042), pleural abscess (PSICIE: 9, 37.5% vs. PSIWIE: 25, 16.3%, p = 0.024), sepsis (PSICIE: 20, 83.3% vs. PSIWIE: 67, 43.8%, p < 0.001), septic embolism (PSICIE: 16/23, 69.6% vs. PSIWIE: 37/134, 27. 6%, p < 0.001) and meningism (PSICIE: 8/23, 34.8% vs. PSIWIE: 21/152, 13.8%, p = 0.030) occurred more frequently in PSICIE than in PSIWIE patients. PSICIE patients received longer intravenous antibiotic therapy (PSICIE: 6 [4-7] w vs. PSIWIE: 4 [2.5-6] w, p < 0.001) and prolonged total antibiotic therapy overall (PSICIE: 11 [7.75-12] w vs. PSIWIE: 8 [6-12] w, p = 0.014). PSICIE patients spent more time in the hospital than PSIWIE (PSICIE: 43.5 [33.5-53.5] days vs. PSIWIE: 31 [22-44] days, p = 0.003). Conclusions: We report distinct clinical, radiological, and microbiological phenotypes in PSICIE and PSIWIE patients and further demonstrate the diagnostic accuracy of the modified Duke criteria in patients with PSI and concomitant IE. In the high-risk population of PSI patients, the modified Duke criteria might benefit from amending pleural abscess, meningism, and sepsis as minor criteria and hepatic cirrhosis as major criterion.

Detection of cranial meningiomas: comparison of 68Ga-DOTATOC PET/CT and contrast-enhanced MRI.

PURPOSE: PET imaging with somatostatin receptor ligands, such as (68)Ga-DOTATOC, is a well-established method for detection and target volume definition of meningiomas prior to radiotherapy. Since DOTATOC PET delivers a higher contrast between meningiomas and surrounding tissues than MRI, we conducted a retrospective analysis to compare the diagnostic accuracy of contrast-enhanced MRI (CE-MRI) with (68)Ga-DOTATOC PET/CT in patients with cranial meningiomas prior to radiotherapy. METHODS: Over a period of 6 years, 134 patients (20-82 years of age, 107 women and 27 men) underwent cranial CE-MRI and (68)Ga-DOTATOC PET/CT. To compare the two methods, the lesions considered typical of meningiomas visually were counted and analysed with respect to their location and SUVmax. RESULTS: In the 134 patients investigated by both modalities, 190 meningiomas were detected by (68)Ga-DOTATOC PET/CT and 171 by CE-MRI. With knowledge of the PET/CT data, the MRI scans were reinvestigated, which led to the detection of 4 of the 19 incidental meningiomas, resulting in an overall detection rate of 92 % of the meningioma lesions that were found by PET/CT. CONCLUSION: Ga-DOTATOC PET/CT demonstrated an improved sensitivity in meningioma detection when compared to CE-MRI. Tumours adjacent to the falx cerebri, located at the skull base or obscured by imaging artefacts or calcification are particularly difficult to detect by MRI. Therefore (68)Ga-DOTATOC PET/CT may provide additional information in patients with uncertain or equivocal results on MRI or could help to confirm a diagnosis of meningioma based on MRI or could help to confirm MRI-based diagnosis of meningiomas in cases of biopsy limitations. It is possible that not only radiotherapy and surgical planning, but also follow-up strategies would benefit from this imaging modality.

Olfactory bulb volume in patients with idiopathic normal pressure hydrocephalus.

INTRODUCTION: An important pathological feature of idiopathic normal pressure hydrocephalus (iNPH) is a dysfunction of cerebrospinal fluid dynamics. Considering the delicate olfactory structures it appears possible that the olfactory bulb (OB) is compromised by this disease. Reports on the anatomy of the olfactory bulb and smell function in patients with idiopathic normal pressure hydrocephalus are absent in the literature. The main purpose of the present study was to evaluate the olfactory bulb (OB) volume and smell function in iNPH. METHODS: The study comprised 17 patients with iNPH (seven women and ten men, mean age = 66 years); they were compared to a group of 24 healthy people (11 women and 13 men, mean age = 62 years). Comprehensive assessment of olfactory function was conducted with the "Sniffin' Sticks" test kit. In an additional pilot study, in a small subgroup of eight patients, measurements were performed before and approximately 7 months after surgical treatment of the hydrocephalus. RESULTS: The OB volume in patients with iNPH was significantly smaller compared to healthy controls. In our small postoperative patient population (n = 8), there was no significant change of the OB volume. CONCLUSION: In conclusion our results suggest that iNPH significantly affects OB volumes.